Person in Capitol, I suspect? (10)
I believe the answer is:
politician
'person' is the definition.
(politician is a kind of person)
'in capitol i suspect?' is the wordplay.
'suspect?' indicates an anagram (a suspicious or unusual spelling).
'in'+'capitol'+'i'='incapitoli'
'incapitoli' anagrammed gives 'POLITICIAN'.
(Other definitions for politician that I've seen before include "Eg, an MP" , "Legislator" , "One in Westminster" , "US senator?" , "could be Congressman" .)